Electromagnetic clutch



-IDec. 14, 1937.

H. E. HODGSON 2,102,318

ELECTROMAGNETIC CLUTCH Filed Nov. 29, 19.35 2 Sheets-Sheet l mm @Q. m

Dec. 14, 1937. v I E HQDGSON 2,102,318

ELECTROMAGNETIC CLUTCH Filed NOV. 29, 1935 2 Sheets-Sheet 2 5 21 N31 MM MMWMAW W5 m- Wm go wmwggilx ?atented Dec. 14, 1937 warren .sra'ras PATENT oer-"1C5 moans nnncraomcnnmc cw'rcn Howard E. Hoflsson, Wauwatosa, Wis, assignor to Cutler-Hammer, Inc., Milwaukee,- Win, a

corporation of Delaware Application Norembcr 29, 1935, Serial No. 52,107 A 8 Claims. (43!. 19%) to facilitate rapid dissipation of the heat generated in the operating winding and also by its friction surfaces.

Another object is to provide a clutch of the aforesaid character having its parts constructed and arranged to provide for ready adjustment of the friction parts and to also facilitate removal of the driven element for inspection or repair. Y

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate an embodiment of the invention which will now be described, it being understood that various modifications may be made in the embodiment illustrated without departing from the spirit and scope of the appended claims.

In the drawings.

Figure 1 is avertical sectional view ofa clutch embodyin the invention;

Fig. 2 iso fragmentary end view of the clutch shown in Fig. 1; and

Fig. 3 is a fragmentary sectional view take substantially on lineal-801158. 2.

The clutch illustrated in the drawings is associated with a flywheel l rotatabiy mounted upon a shaft 2, the flywheel shown having a projecting hub portion I and a projecting rim portion 5 on one side thereof and being supported upon said shaft by roller bearings i; Said clutch includes a driving element consisting of a magnet I mounted upon the left hand face of flywheel l and havinga pair of friction-rings I and 9 associated therewith and a, driven friction ring ll] arranged between the former friction rings and mounted upon a hub H fixed to shaft 2.

specifically magnet I is of annular form and includes, a field member It. on armature member I 3 and a magnet winding ll wound upon an insulating bobbin carried by said field member. Field member l2 and armature member I! are Provided with annular pole projections l5 and 'II, respectively. which surround the winding it,

of and armature member I! is internally threa'dand-annular pole projections i1 and I8, respectively, which are located within said'winding. The pole projections. and it have cooperating pole faces i9 located adjacent the right hand end of winding i4 and the pole projections ll and it have cooperating pole faces 20 located adjacent the left hand end of said winding.

. Armature member it is provided with openlugs for receiving a plurality of spaced bushings 2| which are secured to the face of pole projection ll on field member I 2 by cap screws 22, and said armature member is slidable axially upon said bushings and is biased to move away from said ileld member by a plurality of springs 23. The springs 23 are held within openings in .15

pole projection I! and bear against the facejof pole projection it on armature member. II, and movement of said armature member under the action of said springs is limited by washers 24 Y which are secured to the outer ends ofthe bushings 2| by the cap screws 22.

Field member I! is provided with an inwardly projecting flange 25 which is secured tofrictioif ring 9 by screws 28 and said friction ring is shouldered to fit within the flange 2i and is secured to the left hand face of .flywheel I by screws 27. Friction ring is slidably mounted .within the pole projection if on fleldmember l2 and as shown in Fig. 2 the same'is held against rotation with respect to said field member by gear teeth 22 on the periphery thereof which mesh with gear teeth 29 on the interior of pole projection II. The left hand face of friction ring .8 is provided with an annular projection ll which abuts a thrust ring 3| mounted upon the armture member ll. Thus upon attraction of armature member i3 friction ring I is moved towards the right by thrust ring It to clamp .friction ring II between the same and friction ring 9 to thereby establish a driving connection 4 from flywheel i to shaft 2. v

To insure proper clamping of the friction rings and to also provide for quick release of the clutch it is necessary to adjust friction ring I with respect tothe armature member I! so asto maintain an air gap between the associated pole faces of the magnet upon energizatlon of" themagnet; llorthis vthntstringji has a square thread 82 on th periphery there-' ed to receive the same. To facilitate adiiistment of thrust ring ii the some is provided with an annular projection fl extends beyond the armature member and is provided with openings 33 for receiving a suitable adjusting tool.

Means is provided for holding the thrust ring 3| in adjusted position within the armature member l3, such means comprising a circular locking member 33 mounted within a circular recess 31 in the face of armature member". As shown in Fig. 3 locking member 33 has teeth 38- on one side thereof which engage'with the threads 32 on thrust ring 3| and the same has a tapped opening therein for receiving a cap screw 33 passing through a plate 33 fixed to the face of armature member l3 by screws 40. Cap screw 33 is ofiset with respect to the axis of locking member 38 to prevent turning of said locking member within the recess 31 and said locking member is spaced with respect to plate 31. It is thus apparent that locking member 36 can be drawn towards the left with respect to armature member l3 by the screw 33 to securely lock the thrust ring 3| against turning within said armature member.

As hereinbefore stated, the driven friction ring I0 is mounted upon a hub 3 fixed to shaft 2. Friction ring it has friction linings secured to opposite faces thereof and as shown in Fig. 2 the same consists of two sections l0 and Ill which are clamped between a pair of ring members 42 and 43 by screws 44. The ring members 42 and 43 are slidably mounted upon the periphery of an outwardly projecting flange 45 on hub I I and as shown in Fig. 2 said ring members are held against rotation with respect to hub II by gear teeth 46 on the inner surfaces thereof which mesh with gear teeth 41 on the periphery of said flange.

The magnet winding is provided with suitable terminals 49 which are located within openings in the field member l2 and said terminals are connected by leads 30 to a pair of insulated slip rings 3| mounted on hub 4.

With the parts arranged as hereinbeiore described it is apparent that upon energization of winding l4, armature member I3 is attracted toward field member I! and the thrust ring 3| associated with said armature member then acts to. force friction ring 3 toward the right, whereby the driven friction ring III is clamped between friction rings 3 and 3 to establish a. driving connection between flywheel I and the driven shaft 2. Upon de-energization of winding l4, armature member 3 is moved out of its attracted position under the action of springs 23 and friction ring I is thus released to interrupt the driving connection between flywheel and shaft 2.

Numerous advantages are obtained by arranging the clutch parts in the manner above described. A large flywheel effect is obtained by arranging the field and armature members outside the friction rings. Also the weight of the driven element of the clutch is reduced to a -minimumsothataminimumofpowerwilibe required for acceleration of .said member when t the clutch is engaged. It should also be noted that the thrust ring 3| and friction ring 3 can be removed without disturbing the other parts of the clutch to render the driven friction ring I accessible for inspection or repair and if it is necessary thetwo sections III and Ill" of said ring can bedetached by removing the screws 44.

What I claim as new and desire to secure by Letters Patent is:

i. In anelectromagnetic clutch, in combination, a driving element having cooperating field and armature members of annular form, a pair aioasia of friction elements mounted within the opening in said field member, one of said friction elements being fixed to said field member and the other being coupled directly to said field member to rotate therewith and being movable toward said former friction element by said armature member upon attraction of the latter and a driven friction element to be clamped between said pair of friction elements upon attraction of said armature member.

2. In an electromagnetic clutch, in combination, a driving element having cooperating field and armature members of annular form, a. pair of friction rings mounted within the opening in said field member, one of said friction rings being fixed to said field member and the other being coupled to said field member independent- 1y of said armature member and being movable axially with respect to said field member, an adjustable thrust part associated with said armature member for engaging said latter friction ring to move the same toward said former friction ring upon attraction of said armaturemember and a driven friction ring to be clamped between said pair of friction rings upon attraction of said armature member.

3. In an electromagnetic clutch, in combina tion, a driving element including an annular field member having teeth on the inner surface thereof and a cooperating annular armature member nonrotatably mounted upon said field member and movable axially with respect thereto, a pair of driving friction rings mounted within said field member, one of said friction rin8 being fixed to said field member and the other being movable axially within said field member and having teeth on the periphery thereof which mesh with the teeth on the interior of said field member, a thrust ring adjustably mounted within said armature member for engaging said latter friction ring to move the same towards said former friction ring upon attraction of said armature member, and a driven friction ring arranged between said former friction rings to be clamped thereby upon attraction of said armature member.

4.'In an electromagnetic clutch, in combination, a shaft, 2. driving'fiywheel rotatably mounted thereon, a magnet of annular form mounted upon said flywheel, said magnet including a field member fixed to said flywheel and a cooperating armature member mounted to rotate with said field member and movable axially with respect thereto, a pair of driving friction rings mounted within said field member, one of said friction rings being fixed to said field member and the other being coupled to said field member independently of said armature member and being movable axially with respect to said field member. an adjustable thrust part mounted upon said armature member for engaging said latter friction ring to move the same toward said former friction ring upon attraction of said armature member and a driven friction ring to be clamped between said pair of friction rings upon attraction of said armature member, said driven friction ring being movable axially upon said shaft and being fixed against rotation with respect thereto.

5. In anelectromagnetic clutch. in combination, a shaft, a driving flywheel rotatably mounted thereon, a magnet of annular form mounted upon said flywheel, said magnet including a .fleld member fixed to said flywheel and a cooperating armature member mounted to rotate with said field member and to move axially with respect thereto, a pair of driving friction rings mounted within said field member to rotate therewith, one of said friction rings being fixed to said field member and the other being coupled to said field member independently of said armature member and being movable axially with respect to said field member, an adjustable thrust part mounted upon said field member for engaging said latter friction ring to move the same toward said ,former friction ring upon attraction of said armature member, a driven ring element including a plurality of removable segments to be clamped between said pair of friction rings upon attraction of said armature member, said ring element having teeth on the interior thereof and a hub fixed to said shaft for supporting said driven ring element, said hub having teeth on the periphery thereof to mesh with the teeth on the interior of said driven ring element.

6. In an electromagnetic clutoh in combination, a shaft, a driving flywheel rot'atably mounted thereon, a magnet of annular form mounted upon said flywheel, said magnet including a field member fixed to said flywheel and a cooperating armature member mounted to rotate with said field member and movable axially with respect thereto, a pair of driving friction rings mounted within said field member to rotate therewith, one of said friction rings being fixed to said field member and the other being movable axially with respect thereto, an adjustable thrust part mounted upon said armature member for engaging said latter friction ring to move the same towards said former friction ring upon attraction of said armature member, a. driven friction ring compris ing a plurality of segments to be clamped between said former friction rings upon attraction of said armature'imember, a hub fixed to said shaft for 

